World No 1 Ashleigh Barty may not play the season-ending WTA Finals because of the "ridiculous" playing conditions now it has been moved to Mexico, according to her coach.
The WTA Finals feature the world's top eight singles players and eight doubles teams.
It was supposed to be played in Shenzhen, China, but this week it was announced that it has been switched to Guadalajara in Mexico due to the Covid-19 pandemic.
'She's an upgraded Hingis' - Barty lauded as she approaches No 1 milestone
Barty won the WTA Finals the last time they were held in 2019, but her coach Craig Tyzzer is uncertain if she will defend her title.
"We only just found out it's in Mexico at 1500 metres (above sea level) and they're using pressure-less balls," Tyzzer told the Australian Associated Press.
"Pressure-less balls absolutely fly. It's a ball that, if you use it in normal conditions, it doesn't bounce. It's not the greatest advertisement for the best girls in the world to be playing something they've never done before
In conditions they've never played, in a country they don't play and at altitude, I just feel it's ridiculous. As a spectacle, it's just frightening.
Barty and Tyzzer have been on the road since March and are only set to return home to Australia at the end of the season.
'She looked so comfortable in the biggest moments' - Wilander in awe of Raducanu
- McEnroe defends Raducanu Wimbledon comments
- Laver Cup, Indian Wells - What's left to play for in 2021?
Tyzzer says Barty, who lost in the third round of the US Open this month, is "physically and mentally exhausted" and wouldn’t want to jeopardise her preparations for the 2022 Australian Open by playing in the WTA Finals, which start on November 8.
"Indian Wells (next month) is still on the radar but she just needs a rest. So I told her to just get away and have a holiday.
“It certainly isn't easy for us to get there and to play that event in Mexico and then to come back and have to do two (more) weeks (in quarantine) and then your summer is sort of ruined as well. It's a decision we'll have to sit and mull over quite a bit."
Australian Open: Will players need to be vaccinated? What are quarantine rules?
Barty's coach hits out at 'ridiculous' quarantine decision on Australia return